The present invention pertains to an on-board or off-board diagnostic device for checking a partial system of a motor vehicle, which partial system was manufactured by a special manufacturer, by the motor vehicle manufacturer or the like (xe2x80x9ccustomerxe2x80x9d) for a customer diagnosis by means of the vehicle""s data collection line or vehicle data bus, with an electronic control device, which is associated with the partial system and which is connected, e.g., to an operating device via a line.
An on-board diagnostic device of the above-described type for checking partial systems of a motor vehicle has been known from DE 195 40 943 A1, in which the deviation from the normal course of a control for polling testing and checking routines by entering certain commands to the diagnostic line is made possible, as it had also been described, in principle, elsewhere (see, e.g., IPSO/DAIS 14229 draft from 1995, item 9 xe2x80x9cInput/Output Control functional unitxe2x80x9d and item 10 xe2x80x9cRemote Activation of Routine functional unit;xe2x80x9d IPSO/DAIS 14230 draft from 1995, item 9 xe2x80x9cInput/Output Control functional unitxe2x80x9d and item 10 xe2x80x9cRemote Activation of Routine functional unitxe2x80x9d). As can be determined from the above-mentioned documents, there are many standards and other specifications for the diagnosis of complex electronic systems.
The problem of a special manufacturer of a vehicle partial system or of an outside vendor supplying accessories for motor vehicles is that each vehicle manufacturer requires compliance with his own diagnostic instructions and does not permit any other diagnostic protocols besides it. For example, one vehicle manufacturer requires a diagnosis according to Keyword Protocol 2000 for a heater and does not allow any commands on the data line other than those described in a certain diagnostic specification of the vehicle manufacturer.
However, an outside vendor supplying accessories for. Motor vehicles wants to supply motor vehicle partial systems, e.g., motor vehicle auxiliary heaters (parking heaters), to different motor vehicle manufacturers, but such a vendor must provide a different diagnostic interface for each motor vehicle manufacturer according to the state of the art, taking into account the above mentioned specifications, i.e., a partial system, e.g., a heater, manufactured for a given motor vehicle manufacturer, can be addressed only with the commands of the customer diagnosis associated with the given motor vehicle manufacturer. A diagnostic system of another motor vehicle manufacturer requires correspondingly different commands for the same type of heater. However, the above-mentioned outside vendor of motor vehicle accessories, the special manufacturer of the motor vehicle partial system, including the corresponding on-board diagnostic device, requires a set of commands going beyond the scope. Of functions of the motor vehicle manufacturers with such functions as, e.g., xe2x80x9cProgram data set,xe2x80x9d xe2x80x9cPoll end-of-tape test,xe2x80x9d etc. However, these additional functions are not made available to the motor vehicle manufacturers, mainly for reasons of reliability of function and because of the risk of operating error.
The above-mentioned additional set of commands is handled according to the state of the art via the data line (K line) provided for the customer of the motor vehicle manufacturer, because an additional plug pin with an additional diagnostic interface for the special manufacturer for a special manufacturer diagnosis would mean a rather significant, expensive extra effort. This is also frequently undesirable on the part of the motor vehicle manufacturer, because a hidden switchover from customer diagnosis to special manufacturer diagnosis would mean the possibility of an incorrect activation and a breakdown of the data transmission on the diagnostic bus in the motor vehicle.
Based on the above-described state of the art, the object of the present invention is to provide an on-board diagnostic device of the type described in the introduction, with which the switch over from customer diagnosis to special manufacturer diagnosis continues to be possible, but the switch over is protected such that an accidental switch over is ruled out during normal operation of the vehicle.
According to the invention, an on-board or off-board diagnostic device and system are provided for customer diagnosis or for checking a partial system of a motor vehicle manufactured by a special manufacturer, by the motor vehicle manufacturer or the like (xe2x80x9ccustomersxe2x80x9d). A data collection line of the vehicle or vehicle data bus is used. An electronic control device is associated with the partial system and is connected to an operating device via a control line. The device, system and method of the invention provide a special manufacturer diagnosis which is locked during customer diagnosis. A specially coding signal is fed into the electronic control device on the control line. This unlocks the manufacturer diagnosis for switching over from the customer diagnosis to the special manufacturer diagnosis for the purpose of making available expanded or changed data information on the partial system.
The essence of the present invention is that a specially coded signal is fed into the electronic control device on a line of the system that is already present anyway for switching over from customer diagnosis to special manufacturer diagnosis for the purpose of making available expanded and/or changed data information on the partial system.
The partial system of the motor vehicle is especially a motor vehicle auxiliary heater or parking heater operated in an engine-independent manner.
The line that is present anyway, via which the coded switch over signal is fed in, is preferably the control line and especially the switch-on line of the partial system.
However, the line that is present anyway may also be another, already present line of the motor vehicle partial system or of a component of the partial system.
The coded signal is especially defined rapid on/off switching sequences, which do not compromise the normal on/off switching function of the partial system at the consumer or user.
The coded signal may also be defined voltage levels, which do not compromise the normal function of the partial system at the customer or user.
The switch over between customer diagnosis and special manufacturer diagnosis may be performed in a single-wire system, especially a K line (xe2x80x9cK line diagnosisxe2x80x9d), but also in a multiple-line system, especially a CAN bus.
The separation of the lines is preferably brought about by unplugging the corresponding plugs and installing an adapter plug.
The hardware-side and software-side interlocking of the partial systems, especially of the heater manufacturer diagnostic functions, is thus made possible by the present invention by the use of at least one additional plug pin. Only the original equipment supplier diagnosis can be accessed via the diagnostic line alone. After feeding a certain coding to, e.g., the switch-on signal, it is possible to switch over to manufacturer diagnosis. The additional diagnostic functions of the manufacturer diagnosis are needed especially for the development of the (heating) device (parameterization, read-out, testing, etc.). A special device manufacturer or his service organization can access all control devices for different original equipment suppliers with a uniform software without having to purchase their expensive diagnostic devices. The diagnosis of the original equipment suppliers or customers is not interfered with. Without using the present invention, uniform access to the (heater) control devices in the motor vehicle is not possible. The variety of variants is enormous in this case.
The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and specific objects attained by its uses, reference is made to the accompanying drawings and descriptive matter in which a preferred embodiment of the invention is illustrated.